By using them extensively and completing challenges with the perks
no sir
in any call of duty game with perks, you can unlock the pro "improvement" by creating a class with the perk you want and play with it some time. after getting a certain amount of kills for example you will get the perk improvement
a red dot sight
Their are no cheats yet. You can only get perks so far.
no way MW3 is pro it has no glitches and the graphics are pro
Time and Practice.
First of all, perks are upgraded by completing a series of perk challenges. To get a perk uograded to "pro", you have to complete 4 of the perk challenges. So, to get Overkill Pro you must complete the challenge called Overkill Pro IV, which is completed by getting 120 kills with your second primary weapon.
The perks for the Famas are probably gonna be, Scavenger Pro, Sleight of hand Pro, and Ninja Pro, i mean thats what i recommend.
The pro perks give you extra advantages like , Scavenger pro , gives you more ammo & Sleight of hand pro enables faster ADS (Aim Down Sight).
i no a couple there is cold-blooded pro scavange pro marothon pro and a couple others
15+pro perks if I'm not mistaken
If your talking about online then in create a class go to perks and get ghost and ninja perks(perks 1 and 3) to have them be better perks or be more 'sneaky' u can do the work it has to do then you can upgrade them to pro!